Blender 2.8 - Pro Lighting Sky and Studio -
You have to check on the blendermarket website for version 1.2.4 and download it then just go into user preferences in blender install from file and locate the .zip file. restart pc and it should be there .If you have migrated your settings from 2.79 to 2.8. if you haven't yet then you need to download and install the hdri's to.